"The whole FOX network was in a hot, dense state. Then nearly 14 billion years ago, they began a TV show. Bart tried to sell his soul, Lisa turned to vegetables, Grampa started fighting bulls, Springfield built a wall (The Who played on the top).

"Carl, Lenny, Barney, Moe and a fat, bald guy who hollers, 'D'oh!'. That all started with The Simpsons (D'oh)!"

It's probably lucky that Kaley knows the original theme tune so well though since she'll be hearing it for another two years at least, after it was confirmed in March that The Big Bang Theory will continue through to its 12th season.